SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4d6f822ff257bd6bb9d5e7b7abc34f25c0c615772114a628cac326f399f06130' 
  AND token = 'P/RScIIkOe4uATxvOslLnBNc/dL9dhNxLx0rQ20gOKs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}